​One important way in which society projects influence abroad is through the exercise of diplomacy. Diplomacy began as a means by which a sovereign aimed to prevent aggression from his neighbours, and became, by the end of the seventeenth century, and without diminishing the ceremonial role it had always played, an agency for the settlement of trade and mercantile disagreements, the prevention of wars, or for concluding them after they began, and for the negotiating of marriage alliances.